The present invention relates to a device for sealing inspection apertures, and in particular to a device for sealing inspection apertures in a casing of a gas turbine engine.
Gas turbine engines generally comprise in flow series a compressor, a combustor and a turbine.
It is well known in the gas turbine engine art to inspect the compressor, combustor and turbine sections to assess the condition of the various components. Such inspection of the gas turbine engine comprises passing a viewing instrument through an inspection aperture in the casing of the gas turbine engine. The viewing instruments may be either flexible or rigid, and may be designed for end or angled viewing. The viewing instruments are commonly called borescopes. The viewing instruments allow cracking, wearing or other faults of the gas turbine engine components to be detected. The inspection aperture is commonly sealed by a sealing plate which is mechanically sealed to the gas turbine engine casing.
Unfortunately however it has been found that occasionally when the sealing plate has been removed from the gas turbine engine casing, to allow a borescope to be inserted through the inspection aperture to view engine components, the sealing plate has not been refitted, has been incorrectly refitted or has not been refitted to the correct tightness. The incorrect fitting, or refitting, of the sealing plate allows hot working gases to leak through the inspection aperture when the gas turbine engine is in operation. The leakage of the hot working gases, through the inspection aperture, may cause damage to encircling structure of the gas turbine engine or the relatively high temperature gases may cause any temperature/fire detectors to shut down the gas turbine engine during flight.